A conventional oil sealing system for a turbo charger related to the present invention is disclosed in Japanese Utility model Patent Publication No. 41-1841 published on Feb. 10, 1966, and is shown in FIG. 6. There, a shaft 101 of a turbo charger 100 is rotatably supported in a bearing-housing 102 via bearings 103, 104 and a plate 105. The bearings 103, 104 are lubricated by oil which is supplied through a passage 107. The oil is discharged to an oil-pan (not shown) through a drain-port 113. The plate 105 has a ring-shaped flange portion 105a. A bushing 114 which is located around the shaft 101 has a screw 114a. The rotating direction of the screw 114a is formed against the rotating direction of the shaft 101. Plate 115 is located around the screw 114a.
A compressor-rotor 106 is fixed to an one end of the shaft 101, and a turbine-rotor (not shown) is fixed to the other end of the shaft 101. A rotor-housing 108 is fixed to the bearing-housing 102 by bolts 109, 110. The rotor-housing 108 has an inlet 111 and an outlet 112.
In the above mentioned oil sealing system, the turbine-rotor is supplied exhaust gas, so that the shaft 101 is rotated. Shaft 101, in turn, rotates the compressor-rotor 106. Thus, air in the inlet 111 is sent to the outlet 112.
Oil which lubricates the bearings 103, 104 is drawn toward the outlet 112 by the negative pressure that is generated behind the compressor-rotor 106. The outlet 112 is connected to an intake manifold of an engine (not shown). Thus, it is necessary that the oil leaking is prevented.
In the above mentioned oil sealing system, oil is discharged from the lubricated components, for removal through outlet 113, by the rotation of the ring-shaped flange portion 105a. Oil is directed to the plate 105 by the screw 114a and the plate 115. Therefore, the oil leakage is prevented.
However, this oil sealing system is complicated in construction. Manufacturing of the system requires many steps and involves relatively high costs.